Preparation Of Pd-Fe Nanomaterials Supported On Biocarbon And Its Catalytic Activity

Palladium nanomaterials have been widely studied because of their unique electronic configuration and nano-effects,and exhibit high conversion rates in catalytic reactions.However,due to their high cost and difficult recovery,the design and development of new magnetically recoverable palladium nanomaterials with lower cost by means of doping metals is gradually becoming a hot research topic in this field.In this paper,a Pd nanomaterial and Pd-Fe nanomaterial supported on biocarbon were constructed by adsorption-pyrolysis treatment using yeast residue as the carbon precursor.In addition,the properties and mechanisms of Pd（Ⅱ）and Fe（Ⅲ）adsorption in solution by yeast residue were investigated,Pd nanomaterials and Pd-Fe nanomaterials supported on biocarbon were prepared,the synthesis mechanism of the materials was explored,and their catalytic activities in the reduction reaction of p-nitrophenol were evaluated.This paper provides a theoretical basis and technical support for new methods of synthesis of magnetically recoverable noble metal nanomaterials and their practical applications.The main conclusions of the paper are as follows:Firstly,the kinetic model shows that the individual/co-sorption of Pd（Ⅱ）and Fe（Ⅲ）by yeast residue fits the pseudo-second-order kinetic model which means the process was chemisorption.The isothermal adsorption study showed that the linear Langmuir model fitted the adsorption process well,indicating that the process was monomolecular layer adsorption.FT-IR results showed that there were differences in the functional groups of Pd（Ⅱ）and Fe（Ⅲ）by yeast residue individual/co-sorption.Secondly,Pd nanomaterials supported on biocarbon were prepared,which were porous in structure and loaded with Pd nanocrystals in face-centered-cubic structure.In the catalytic reduction of p-nitrophenol,the material could achieve 96.57%catalytic reduction efficiency in 2minutes with an apparent rate constant k value of 3.58×10^-2/s,indicating that the material has excellent catalytic activity.Thirdly,Pd-Fe nanomaterials supported on biocarbon were prepared,which were porous and loaded with simple-cubic structured Fe Pd₃nanocrystals,and the saturation magnetization strength,remanence and coercivity of Pd-Fe nanomaterials supported on biocarbon were influenced by the pyrolysis temperature during material preparation.The material achieved a catalytic reduction of 99.09%of p-nitrophenol at 25 s under optimized conditions,and similar conversions（96.6%-98.9%）were observed in six consecutive cycles of the reaction.In summary,porous microbial carbon-loaded Pd nanomaterials and Pd-Fe nanomaterials were constructed in this study.In addition,the strong magnetic properties of the microbial carbon-loaded Pd-Fe nanomaterials allow them to be reused by magnetic separation,which has the potential for industrial applications.